For various reasons it becomes advisable to replace the valve stem seals provided on some overhead valve internal combustion engines of the type presently utilized to power motor vehicles. The valves of an overhead valve combustion engine are usually readily accessible, insofar as the ends thereof remote from the valve heads are concerned, by the removal of one or more valve covers provided for the purpose of enclosing those portions of the valves disposed exteriorly of the cylinder head casting. After the valve covers have been removed the valve retainers and keepers therefor may be displaced relative to the valve stems in order to release the keepers for removal of the valve spring retainers and valve springs, after which removal the valve stem seals are exposed.
While various structures have been heretofore provided for displacing the valve spring retainers and valve springs sufficiently to remove the valve spring retainer keepers once a cylinder head has been removed from its associated cylinder block, removal of a cylinder head from an overhead valve combustion engine merely in order to allow replacement of the valve stem seals constitutes an excessive amount of labor in order to accomplish a reasonably simple replacement task.
Various forms of tools previously designed for use in compressing valve springs after the associated cylinder head has been removed from its companion cylinder block are disclosed in U.S. Pat. Nos. 1,621,237, 1,849,538, 1,858,372, 2,524,949, 2,566,460, 2,865,049 and 3,286,330.